Question

why are the hills cooler during the summer?​

Answer 1

Explanation:

$\huge\mathfrak\red{Answer}$

The hills are cooler during summer as air density decreses up the hills so does the temperature. Air becomes cooler with altitude because the heat is lost by radiation from the earth and as the air expands, it cools.

Answer 2

The main Reason is ⬇️

As one goes from the surface of the earth to higher altitudes, the atmosphere becomes less dence and temperature decreases.